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Search Results: 1 - 10 of 4888 matches for " 单卫星 "
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非致病微生物在植物-病原菌协同进化中的作用
卫星
生态学杂志 , 1993,
Abstract: ?
植物附生微生物与叶部病害生物防治研究进展
卫星
生态学杂志 , 1992,
Abstract: ?
基于gateway技术的植物表达载体的构建
郭姗姗?,张 蒙?,卫星
西北农林科技大学学报(自然科学版) , 2010,
Abstract: 【目的】为方便基于植物瞬时表达技术的高通量功能基因筛选,利用gateway技术实现植物表达载体和表达文库的构建,将35s启动子和gateway技术入门载体pdonr222的同源重组区连接到植物表达载体pcambia0380上,构建gateway技术兼容的植物表达载体。【方法】分别扩增35s启动子与pdonr222上attp特异识别序列之间的功能区,并将其依次连入根癌农杆菌(agrobacteriumtumefaciens)介导的植物表达载体pcambia0380的多克隆位点区,利用带有attb特异识别区域的gus基因,对构建的载体功能进行测试。【结果】成功构建了基于gateway技术的植物表达载体p1104d;载体重组基因的选择性测试结果表明,p1104d对目的基因片段的大小无严格选择性;载体重组效率测试结果表明,p1104d重组平均滴度为5.11×105cfu/ml;gus报告基因瞬间表达试验结果表明,改造后的载体可以实现目标基因的顺利表达。【结论】基于gateway技术的植物表达载体p1104d的构建,为实现cdna文库的高效构建和目标基因的高通量功能筛选提供了可能,有望推动植物病原互作研究中关键基因的鉴定与克隆。
热防护系统单自由度动态特性理论模型
黄杰,卫星,,先阳
- , 2019,
Abstract: 本文针对防热瓦的加速度响应以及应变隔离垫(SIP)的动强度问题,提出了热防护系统(TPS)随机振动单自由度动态特性理论模型,并且考虑了SIP的线性刚度和非线性刚度;推导了线性理论模型的解,并且研究了非线性理论模型的迭代求解流程;将有限元分析结果与线性理论解进行了对比,验证了线性理论模型的合理性。对比了非线性理论模型与线性理论模型的解,结果表明:SIP非线性刚度对动态响应具有重要影响,且SIP等效线性刚度系数与激励的类型有关;最后研究了外载荷大小对非线性理论模型的等效线性刚度系数和系统响应的影响规律,结果表明载荷大小的增加会导致系统等效线性刚度的增加,并且响应也随之提高。本文的研究工作为防热瓦的加速度响应、SIP的动强度和TPS动态完整性分析提供了理论依据。
Abstract:A single degree of freedom random dynamic theoretical model for the thermal protection system (TPS) is proposed to study the acceleration response of tile and dynamic strength of the strain isolation pad (SIP). The linear and nonlinear stiffness of SIP is considered. The solutions of linear theoretical model are derived, and the iterative solving procedure of nonlinear theoretical model is studied. The rationality of linear theoretical model is verified by comparing linear theoretical solutions with the results of finite element analysis. The theoretical solutions of nonlinear and linear theoretical models are compared. The dynamic responses and the equivalent linear stiffness coefficient are related to the nonlinear stiffness of SIP and the types of excitations. Finally, the influence laws of the equivalent linear stiffness coefficient and the responses on the external loads are studied. The equivalent linear stiffness and the responses are increases with increasing of the external loads. The investigations in this paper provide a theoretical basis for the researches of the acceleration response of tile, dynamic strength of the SIP and the dynamic integrity of the TPS.
STUDIES OF METHOD OF THE SPORANGIA PRODUCTION AND DIL UTION OF THE ZOOSPORE SUSPENSIONS FROM PHYTOPHTHORA BOEHMERIAE
棉铃疫病菌孢子囊产生及游动孢子悬液稀释的方法

Shan Weixing Li Junyan,
卫星
,李君彦

微生物学通报 , 1993,
Abstract: 本文报道棉铃疫病菌即苎麻疫霉菌(Phytophthora boehmeriae)孢子囊的离体生产及游动孢子悬液的稀释方法。将疫病菌菌饼置于马铃薯葡萄糖培养液(PDL)或菜豆葡萄糖培养液(BDL)中,24C条件下暗培养48—72小时,然后将菌丝块在20-22℃条件下用矿质盐溶液(MSS)更换漂洗(4次)培养10-12小时并辅以光照(日光灯);最后除去MSS,继续光照培养12小时即可得到大量孢子囊。黑暗条件可抑制孢子囊的形成而促进卵孢子的产生。培养液采用BDL优于PDL,除了产孢量更高外,突出的
铁皮石斛疫病及其病原菌
李静,张敬泽,吴晓鹏,卫星,徐同
菌物学报 , 2008,
Abstract: 铁皮石斛疫病2001年发现在浙江义乌栽培田间,是由疫霉菌引起的。在田间,疫霉菌侵染茎基部,引起当年移植苗根腐、植株枯萎和死亡,但侵染2-3年植株幼嫩顶部仅引起顶枯症状。通过对病原菌形态学、交配型的观察,以及核糖体DNAITS序列分析,侵染铁皮石斛的5个分离菌株被鉴定为烟草疫霉菌Phytophthoranicotianae。致病性试验表明,铁皮石斛是烟草疫霉菌的寄主。
dna指纹分析在植病真菌群体遗传研究中的应用
卫星,陈受宜?,康振生?
西北农林科技大学学报(自然科学版) , 1995,
Abstract: 在总结植物病原真菌遗传标记的应用发展过程基础上,着重以重复序列为基础的dna分子标记的应用,综述了近年来dna指纹分析在植物病原真菌群体遗传分析中的应用。还简要讨论了群体遗传分析对植物病理学的深远影响。
地铁振动的传递及对建筑物的影响实测与分析
盛涛,张善莉,伽锃,卫星
- , 2015, DOI: 10.11908/j.issn.0253-374x.2015.01.008
Abstract: 在上海市某软土场地对地铁隧道诱发的三向环境振动进行了监测,结合连续小波变换及1/3倍频程分频振级,对隧道内与自由场地的振动频谱特性及传递规律等进行了分析,同时对邻近建筑的室内舒适度作了评估.测试结论包括如下方面:①轨道扣件上的三向振动表现出明显的宽频和冲击振动特性,经隧道衬砌的第1层滤波效应后,传递至其中部的竖向和横向振动均相对平稳,且衰减效应明显.②传递至自由场地的三向振动,经土层的反射和折射效应后,呈现出与列车编组对应的冲击振动特性;其与衬砌上的频率成分基本相似,但振幅衰减效应不如衬砌,甚至会出现一定幅度放大.③经建筑墙体的第3层滤波效应后,竖向振动传递至楼板后其频率成分单一,对室内舒适度影响很大,其分频振级的峰值位于楼板的竖向自振频率处,是影响室内舒适度的决定性因素.④地铁引起的地面高频振动激发了建筑结构的水平向高阶振型,对部分楼层的舒适度具有潜在影响,应引起注意.上述测试结论有助于为地铁环境振动有针对性地设计相应减振及隔振措施提供参考.
The three dimensional environmental vibrations induced by a shallow buried subway in Shanghai were in situ measured. By applying with continuous wavelet transform and 1/3 octave frequency vibration level, the vibration transferring characteristics between the tunnel and the open field were analyzed. Simultaneously to the human comfort inside a nearby six story residential building. Testing results include 4 aspects: ① the 3 D vibrations on rail pads were characterized by wide banded and shocking. The vertical and transverse vibrations were relatively smooth after transferred to the center of lining, but amplitudes attenuated greatly. ② The 3 D vibrations in the open field transferred from lining were obviously shocking vibration characteristics corresponding to the carriages. The frequencies were the same with the lining, but the amplitudes attenuated smaller, sometimes maybe magnified. ③ After transferred through the third filter system represented by the masonry walls of building, the vertical resonance frequencies of floor slabs were corresponding to the peak values of the vertical octave vibration levels in this testing, and were the main factor influencing the human comfort inside building. ④ The horizontal high frequencies transferred from subway tunnel have potential influences on some floors’ human comfort, need to be paid more attentions. The above measurements will be benefited to the design of vibration reduction methods to railway vibrations specifically
钢连桥人致振动及TMD减振效应实测与分析
Analysis and In-situ Test of Human-Induced Vibration for the Steel Footbridge with and Without TMD Devices

王洪涛,卫星,韩建平,伽锃
- , 2016, DOI: 10.16450/j.cnki.issn.1004-6801.2016.03.016
Abstract: 以某室外大跨轻柔钢结构人行桥为案例,介绍了该结构的设计概况及调谐质量阻尼器(tuned mass damper,简称TMD)减振设计,分别在结构施工完成后以及TMD装置安装后对其进行了实地动力测试,测得了该结构减振前后的模态特性以及在多种人行荷载工况下的振动响应,采用加速度峰值和均方根值为评价指标,分析了钢连桥人致振动情况及特性。结果表明:一端设计为滑动连接的钢连桥人致振动主要由第1阶竖向振型控制,扭动及水平振动响应相对较小;安装经优化设计的TMD装置后,整体连桥的频率特性没有明显变化,分布式TMD对多种频率激励工况均有良好的调谐减振作用,减振率达到35%~70%;共振激励下测得的原结构阻尼比较小,安装TMD后结构的阻尼比提高4倍,并且呈现出在自由振动衰减的前期较大,随着振动幅度变弱阻尼比降低;测试中发现TMD装置的减振效率对其阻尼比的变化不敏感。
A steel structure footbridge characterized by its flexibility and long span is taken as a case. The designs of the structure and tuned mass damper (TMD) systems are introduced. In situ measurements are conducted after construction and after the installation of TMD devices. Then, the modal properties and vibration responses under various pedestrian load conditions with or without TMD devices are obtained. The human-induced vibration properties are analyzed based on the acceleration peak and acceleration root mean square (RMS) value. The results indicate the following: The vibration of the steel footbridge is dominated by the first vertical mode when one end of the bridge is designed as a sliding connection, and the torsional and horizontal vibrations are relatively small. There is no obvious difference in the vibration properties of a footbridge after TMD devices are installed. The distributed TMD produces good vibration tuned effects for the various excitation conditions with reduction ratios of 35%-70%. Moreover, the damping ratio increases over four times the value without TMD, which is very small before installation. The damping is large at the earlier stage of the free attenuation response and decreases with decreasing vibration amplitude. Lastly, the TMD′s efficiency in vibration reduction is insensitive to variation of the TMD damping ratio.
地铁诱发的环境振动及振源减振效应的实测与分析
In-situ Measurement and Analysis of Subway-Induced Environmental Vibrations and the Effectiveness of Vibration-Source Suppression Methods

盛涛,张善莉,伽钲,卫星
- , 2015,
Abstract: 以上海市某地铁线路邻近的六层砌体结构居民建筑为例,通过现场实测,分析了地铁诱发的三向环境振动对室内舒适度的影响程度及主要影响因素;分别在更换了高弹性扣件和降低了列车行驶速度之后,再次对三个正交方向的室内舒适度进行了实测。结果表明:a.地铁环境振动主要引起室内楼板的竖向振动,其振级与楼板竖向自振频率直接相关,且沿楼层往上逐层减小,顶层楼面相对于首层可减小约5 dB;b.楼板的水平向振动主要受整体结构高阶振型的影响,在某些特定楼层可能出现舒适度超标;c.更换高弹性扣件能明显减小室内楼板的竖向振级,在峰值处可减小约10 dB,但也明显放大了其纵向振级,对横向振动的控制效果不明显;d.降低列车行驶速度对三个正交方向的室内舒适度均具有明显的提升效果,竖向振级在峰值处减小约8 dB,横向和纵向振级最大减小约30 dB,可用于某些环境振动敏感区域进行振动控制。
Human comfort inside a building that encounters subway-induced vibrations is analyzed with in situ measurement, taking a six-story masonry building near a subway line in Shanghai as an example. Relative parameters in three directions are measured and analyzed after replacing a new kind of high elastic fastener or slowing down the average speed of trains, respectively. The results indicate that: a. subway-induced vibrations mainly cause the vibration of floor slabs in the vertical direction. The level of vertical vibration is related to the resonance frequencies of the floor slabs, and the values gradually decreaseon higher stories, as seen in the fact that the vibration level on the 6thfloor slab is 5 dB lower than that of the 1stfloor. b. The horizontal vibration level of the floor slabs is mainly affected by the structure′s higher modes. The level will exceed the limited standard values under certain special conditions, so more attention needs to be paid on human comfort in horizontal directions. c. The new kind of high elastic fastener can reduce the floor slabs′ vertical vibration level by nearly 10 dB, but it amplifies the longitudinal vibration level and has little effect on the transverse vibration levels inside the building. d. By slowing down average train speed, human comfort in three orthogonal directions inside the building is enhanced, with the peak values of the vertical vibrations reduced by nearly 8 dB and the horizontal vibrations by 30 dB at maximum. Thus, it can be used to control the vibration level of nearby buildings in sensitive regions when combined with other effective methods.
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